Ducati Monster Motorcycle Forum banner

Throttle Bodies (not monster related - but tech non the less)

499 Views 3 Replies 3 Participants Last post by  brad black
after doing some research on motorcycle throttle bodies, i'm noticing that some of GSXR throttle bodies actually have 8 injectors?!
anyone know why?
i figured one set is primary, and the other secondary, but i can't figure out why you wouldn't just use 4 appropriately sized injectors
1 - 4 of 4 Posts
For the same reason Ducati used 2 injectors per cylinder on some of the Superbikes. They are turned on in stages based on RPM. You can get better fueling that way, or so the theory goes.
ok, that's what i thought
it can let you run two smaller injectors that have longer opening times and therefore work a bit more consistantly - makes the opening time less of a percentage of total on time.

or you can run one low (under throttle) and one high (shower type), which can have benefits in power output thru the rpm range, using the appropriate injector as required.

the ducati system was used a bit badly - the early 851sp had smaller red or black injectors that ran at full duration (not duty cycle, but the max the map could give) at the torque peak, which is why the race bikes ran 5 bar regs. if they'd used two green injectors they'd have had a heap of fuel.

then on the later sp and sps they bought the switch time down quite low so they were working as duals most of the time anyway, and straight dual, not staggered, etc.
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.